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Valgus Instability of the Elbow in Athletes
ARTHROSCOPIC SURGERY FOR ATHLETIC ELBOW AND WRIST INJURIES
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VALGUS INSTABILITY OF THE ELBOW IN ATHLETES Jon Hyman, MD, Nathan M. Breazeale, MD, and David W. Altchek, MD,
Valgus instability of the elbow is uncommon in the general population and is not seen often in most athletes. Individuals who throw repeatedly, especially baseball pitchers, represent most of these exceptional cases where valgus instability can be identified. The extreme valgus loads generated by the throwing motion place tremendous tensile stress across the medial elbow joint and the ligaments that stabilize it. These forces peak at the medial elbow during late cocking and early acceleration phases of throwing, as the elbow moves from flexion to extension at speeds that have been estimated to reach 3000 deg/sec." The load produced during a typical fastball thrown by an elite pitcher has been estimated to approach the tensile strength of the medial collateral ligament," confirming the notion that pitching is a high-risk activity for the medial collateral ligament. Subtle injury to the ulnar collateral ligament can lead to disabling instability in the throwing athlete in the setting of repetitive valgus stress.4,9, 25, 32, 38, 41, 52,58 When instability prevents return to competition in the overhead athlete, surgical reconstruction often is indicated. Valgus instability can be detected at a much lower incidence in javelin throwers, tennis players, or trauma. Complete ulnar collateral ligament injuries are rare in racquet sports, but repetitive valgus overload can lead To recurrent episodes of microtrauma and subsequent symptomatic valgus in~tabi1ity.l~ Elbow dislocation can rupture the ulnar
From the Sports Medicine and Shoulder Service, The Hospital for Special Surgery, Comell University Medical Center, New York, New York (JH, DWA); and Private Practice, Austin, Texas (NMB) CLINICS IN SPORTS MEDICINE VOLUME 20 * NUMBER 1 'JANUARY 2001
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collateral ligament or avulse it from the medial epicondyle.12Recurrent instability after a simple elbow dislocation is rare. Acute instability generally is not seen if the flexor-pronator muscle group remains intact.55 CLINICAL ANATOMY
A thorough understanding of the anatomy and biomechanics of the elbow are essential in diagnosing and treating injuries of the elbow ulnar collateral ligament (UCL).34, 51 The UCL consists of an anterior bundle, a posterior bundle, and transverse fibers (Fig. 1).The anterior bundle has been shown to be the primary restraint to valgus stress at 30°, 60°,and 90" of elbow fle~ion.~, 22, 32-34* 42, 46, 55 The anterior bundle of the UCL is the most discernible of the three portions of the ligament complex. Its margins are readily distinguished from the surrounding joint capsule and its fibers often are associated intimately with the deep surface of the flexor mass.M,51 The posterior bundle consists of a less distinct fan-shaped thickening of the posterior capsule.MThe transverse fibers originate and insert on the ulna, covering a bony depression on the medial portion of the trochlear notch, and contribute little or nothing to the stability of the elbow. The anterior bundle is the most important portion of the complex when treating valgus instability of the elbow. The ligament originates from the anterior inferior surface of the medial epicondyle. The width of the origin varies but in most cases occupies the middle two thirds to three quarters of the epicondyle in the coronal plane40 (Fig. 2). A small space remains between the lateral edge of the ligament and the medial crista of the trochlea, allowing for a synovial reflection in the joint, 367
Posterior bundle Transverse ligament Figure 1. The anterior bundle of the ulnar collateral ligament is the primary stabilizer of the elbow-resistingvalgus stress. (From Jobe FW, Elattrache NS: Diagnosis and treatment of ulnar collateral ligament injuries in athletes. In Morrey BF (ed): The Elbow and Its Disorders. Philadelphia,WB Saunders, 1993.)
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Figure 2. The anterior part of the medial epicondyle removed by orthogonal osteotomies. On the right a 2 mm thick slice through the widest portion of the origin of the anterior bundle of the ulnar collateral ligament. (From O’Driscoll SW, Jobszynski R, Morrey BF, et at: Origin of the medial ulnar cokateral ligament. J Hand Surg [Am] 17:164-168, 1992; with permission.)
readily visualized on MRI. Morrey and An found the mean length of the anterior bundle to be 27.1 ? 4.3 mm and the mean width to be 4.7 k 1.2 mm.34The anterior bundle inserts on the medial border of the coronoid at the sublime tubercle.34,51 Timmerman and Andrews have defined the histology and arthroscopic anatomy of the anterior bundle.51The medial capsule consists of a synovial lining with two distinct capsular layers between which pass the anterior and posterior bundles.51The anterior bundle consists of welldefined collagen bundles in parallel arrangement typical of ligaments. In cross section, the bundle consists of two portions: one layer between the two synovial layers of the joint capsule, and a second layer superficial to the capsule blending with the deep surface of the flexor mass. The posterior bundle consists of a smaller area of collagen in the capsular layers. FUNCTIONAL ANATOMY
Understanding the functional anatomy of the ulnar collateral ligament requires a synthesis of the kinematics of elbow motion with the biomechanics of the throwing mechanism. The ulnohumeral joint is a hinge or ginglymus joint permitting flexion and extension. The articulation between the greater sigmoid notch of the olecranon and the humeral trochlea is one of the most congruous and constrained joints in the body.
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With loading, the elbow flexors and extensors tend to seat the olecranon in the humeral trochlea, contributing valgus stability under dynamic conditions. Biomechanical studies on the loaded and unloaded cadaveric elbow by Morrey et a1 demonstrated decreased valgus laxity against a gravity valgus stress in the loaded specimens compared to the unloaded specimens both before and after sectioning the anterior bundle of the ulnar collateral ligament.36 The anterior bundle of the ulnar collateral ligament has been shown to be the primary restraint to valgus stress and the radial head a secondary restraint.=,36, 46 With anterior bundle sectioning, the resultant instability is greatest between 60" to 70" and least at full extension and full flexion.& The flexion-extension axis or center of rotation of the elbow lies in the center of the trochlea and capitellum as viewed from the lateral projection.30,35 The origin of the anterior bundle of the ulnar collateral ligament lies slightly posterior to the rotational center of the elbow. The anterior bundle is divided further into an anterior band and a posterior band.43The eccentric origin of these components of the anterior bundle in relation to the rotational center through the trochlea creates a cam effect during flexion and extension. The anterior band tightens during extension and the posterior band tightens during flexion. This reciprocal tightening of the two functional components of the anterior bundle allows the ligament to remain taut throughout the full range of flexion despite its eccentric origin in relation to the rotational center of the BIOMECHANICS OF THROWING
Rupture of the ulnar collateral ligament in athletes has been documented in several sports, but most cases occur in throwing athlete^.^, ~ 5 , 27, 54 An understanding of the throwing mechanism and its relationship to injury is essential in treating ulnar collateral ligament tears. The transition from the late cocking phase to early acceleration places extreme valgus stress on the medial structures of the e1b0w.I~The anterior bundle of the UCL receives the greatest tensile stress as the primary restraint.22,36, 46 Laterally, the radial head is a secondary restraint to the valgus load and receives significant compressive and shear stresses.22, 36, 46 It has been estimated that between 100 and 120 Nm of varus torque is required to resist the valgus stress produced by the throwing motion in elite level Electromyographic data on throwers with normal elbows and those with UCL instability show that the muscles positioned to function as dynamic stabilizers of the medial elbow, specifically the flexor carpi radialis, pronator teres, and flexor carpi ulnaris, do not appear to compensate for UCL laxity and in fact showed slightly decreased activity in the UCL-insufficient pitchers during thr~wing.'~, 56 This suggests there is limited ability for dynamic stabilization of the medially unstable elbow in high-demand throwers.
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HISTORY
A detailed history and physical examination is essential in evaluating the elbow for UCL insufficiency. Most athletes presenting for evaluation are involved in repetitive overhead activities. Knowledge of previous elbow injuries and treatments is important in the initial work-up. The chronology of the development of elbow pain can give clues to the underlying pathology and indicate the injury's severity. A history of mild pain following a return to overhead activities or a significant increase in activity intensity or duration suggests an overuse syndrome. This generally responds to conservative measures directed at the inflammatory response following overuse. These athletes often are able to continue throwing at 100% but develop pain after use. Medial elbow pain with throwing beyond 60% to 75% effort can suggest ligament attenuation.', 5, 54 These athletes often have a history of recurrent medial elbow injury and can sense "movement" or crepitation in the elbow when attempting to throw beyond 75%. In long-standing cases of UCL insufficiency, the athlete can experience mechanical symptoms, such as locking and catching, suggestive of loose bodies or early degenerative changes in the joint. Some throwers report radiating paresthesias into the ulnar fourth and fifth digits. In contrast to this gradual development of UCL insufficiency, some athletes with or without previous elbow symptoms can experience an acute rupture of the ligament. They often will complain of a sudden, sharp pain over the medial elbow. They often can identify the exact moment or pitch that symptoms developed and can experience a "pop" at the moment of ligament rupture. Medial elbow opening with valgus stress can cause ulnar nerve stretching with paresthesias radiating into the medial forearm, hand, and 4th and 5th digits. The pitcher sometimes is able to continue throwing, often with an alteration in throwing mechanics, but is not able to exceed a 75% effort. PHYSICAL EXAMINATION
Physical examination of the elbow for UCL injury entails assessing the integrity of the ligament and evaluating the joint and surrounding structures for associated injuries. Inspection of the upper extremity in overhead athletes often reveals hemihypertrophy of the dominant ext ~ e m i t yElbow . ~ ~ range of motion can be limited by pain or guarding in acute cases. In chronic cases, especially in throwers, motion can be limited at terminal extension due to bony changes in the posterior compartment, capsular contracture, or loose bodies in the olecranon fossa. Crepitance with motion suggests the presence of loose bodies or degenerative changes in the joint. Palpation over the ligament usually elicits tenderness along its course when acute injury is present. The ligament originates at the distal
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anterior portion of the medial epicondyle of the humerus and inserts on the sublime tubercle or medial eminence near the coronoid process.40,51 Pain at the ligament origin can mimic medial epicondylitis or in extreme injury, rupture of the flexor-pronator origin. Pain from the conjoined tendon usually can be elicited with resisted wrist flexion, resisted forearm pronation, or a firm fist clench, differentiating this clinical entity from UCL injury. Injury to the insertion of the UCL is well distal to the medial epicondyle and is differentiated by location of the point tenderness. Identification and palpation of the ligament can be facilitated by using the "milking maneuver."56During examination, the patient places the opposite hand under the elbow to grasp the thumb of the affected arm. With the injured elbow flexed greater than 90" a valgus stress is applied to the elbow by pulling on the thumb. This hyperflexion tends to isolate the anterior bundle of the UCL and the valgus stress places the anterior bundle on stretch. Positioning the elbow in this fashion facilitates location and palpation of the tensioned ligament under the mass of the flexor-pronator origin. Positioning for the maneuver alone can elicit pain over the medial elbow as the anterior bundle is placed on stretch. Valgus stability of the elbow is best examined with the elbow positioned in approximately 90" of flexion, freeing the olecranon tip from the fossa p~steriorly.~ Forearm pronation and wrist flexion relax the flexor-pronator mass, allowing isolation of the UCL. The pronated hand can be held in one of the examiner's hands, or alternatively between the examiner's trunk and arm, while the examiner's other hand is placed on the lateral side of the elbow and a valgus stress is applied to the arm. The ligament is palpated for tenderness during application of the valgus stress. The degree of joint opening and quality of the ligament end point also are assessed with the maneuver, and the affected arm is compared to the asymptomatic side. Even with complete ligament rupture, the side-to-side difference in joint opening can be only 3 to 4 mm and the end point feel can be subtle, making the maneuver difficult to master. We recommend a variation of the stress test to aid in sensing the degree of medial joint opening. After applying valgus stress and palpating the end point, place a varus stress on the elbow. It is often easier to sense the amount of joint opening by the extent of joint line closure in moving from the valgus to varus stress. The end point palpated with a varus stress as the ulno-humeral articulation closes is firm and discrete, and can assist the examiner in determining the amount of medial joint laxity. Complete examination of the elbow with suspected UCL injury requires assessment of other medial elbow structures. Ulnar nerve irritation can be mistaken for ligament injury or can occur in conjunction with it. Bony hypertrophy, medial joint spurring, or inflammation associated with UCL injury can compress the ulnar nerve in the cubital tunnel. Nerve subluxation, especially during the late cocking throwing phase, can lead to medial elbow pain. Careful neurologic examination is essen-
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tial in the work-up to rule out isolated or associated ulnar nerve pathology. Examination of the nerve should focus on nerve sensitivity and tenderness, presence of a Tinel's sign, and distal sensory and motor function. Nerve stability also should be assessed, looking for hypermobility or anterior subluxation. Nerve involvement associated with UCL incompetence can require transposition in conjunction with ligament reconstruction. Valgus extension overload associated with throwing can lead to several well-recognized bony changes across the posteromedial Olecranon tip spurring and osteophyte formation, along with bony hypertrophy of the olecranon fossa and loose body formation, can lead to impingement of the olecranon tip in the fossa at terminal extension, especially in throwing athletes. Pain is elicited with snapping extension of the elbow. Chondral injury and degenerative changes of the posterior joint also can create medial elbow pain similar to that experienced with UCL tears. Application of a valgus stress with the elbow in extension can reproduce pain in cases of posteromedial pain. All sources of medial elbow pain must be explored and any concurrent pathology must be addressed at surgery for a successful outcome in UCL reconstruction. IMAGING STUDIES
Radiographic evaluation is helpful in evaluating the elbow for ligament injury. Plain radiographs can identity degenerative changes and loose bodies in the elbow. Chronic UCL injury can cause calcification along the course of the ligament and medial joint line spurring. The posteromedial osteophyte is seen easily on the anteroposterior view and the hyperflexion lateral view of the elbow as the tip of the olecranon is advanced out of the fossa. Secondary degenerative changes also can be seen at the radiocapitellar joint and at the ulno-humeral joint in longstanding UCL insufficiency. Stress radiographs can be useful in the work-up but have been shown to be negative in known cases of UCL rupture.u, 24 Computed tomographic (CT) arthrography can be helpful in diagnosing an undersurface tear of the ligament.52,53 Extracapsular contrast extravasation with CT arthrography is seen with complete UCL tears. In a study of preoperative assessment of the UCL using CT arthrography and MR imaging (MRI), specificities were 91% and 100%, re~pectively.~~ MR imaging become the study of choice in evaluating the elbow with suspected UCL injury. Integrity of the ligament and associated injuries are readily seen. With the elbow in extension, the anterior bundle is well visualized on coronal section (Fig. 3), allowing differentiation of proximal, distal, or midsubstance ligament tears. MR imaging also allows evaluation of the articular surfaces and adjacent neuromuscular structures for any abnormalities identified on physical examination or radiographic evaluation. MR imaging also can be used postoperatively to evaluate graft integrity, placement, or reinjury. Because of the small
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Figure 3. Coronal gradient recoiled MR image of the left elbow demonstrates the anterior bundle of the medial ulnar collateral ligament. (Courtesy of Hollis G. Potter, MD, New York, NY.)
size of the ligament, technical considerations such as arm positioning, signal-to-noise ratio, and signal sequencing are important in producing an optimal image.31At our institution, MR imaging is performed using a 1.5-T scanner and elbow coil with 3-mm coronal sections through the medial collateral ligament (MCL).Our experience has demonstrated that the addition of intra-articular contrast agents (e.g., gadolinium) is not necessary to detect tears of the MCL. Because many tears are incomplete and therefore the leaking of contrast agent would not be seen. NONOPERATIVE TREATMENT
Treatment options for UCL injuries vary according to the severity of the injury and the patient's athletic requirements. For ligament strains, the basic principles for any ligament injury apply: cold and heat therapy, rest, nonsteroidal anti-inflammatory agents, range-of-motion exercises, therapeutic modalities, strengthening, and a gradual return to sport participation. For overhead athletes, a multidisciplinary approach to recovery is used, including the athletic trainer, therapists, coaches, and physician. Special attention to sport technique, especially with pitchers, should be used to avoid technical errors that place excessive valgus stress on the medial elbow.' Temporarily changing playing position to one that is less throwing intensive can aid the recovery process. Many nonpitchers with chronic UCL laxity can adapt their throwing technique to minimize valgus stress and remain active. Pitchers with laxity tend to
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develop symptoms with repetitive attempts at throwing beyond 75% effort. As with chronic UCL laxity, acute ligament rupture in nonthrowers can be managed conservatively. Nonthrowing athletes rarely have significant pain or dysfunction once the initial inflammatory phase resolves, and the athlete can return gradually to most sports. Valgus-loading upper extremity maneuvers (e.g., javelin throwing, volleyball or tennis serving), and baseball throwing) do not respond as well to conservative treatment and often require surgery to return to preinjury level of function. Rehabilitation of symptomatic UCL laxity or complete ligament rupture has had poor results in returning these high-demand athletes to their previous level of function. Electromyographic analysis in UCL-deficient throwers showed a paradoxical inhibition of muscle recruitment of the flexor-pronator mass during throwing compared to normal throwing elbows.19,2o This could imply that, despite this muscle group’s ideal orientation to compensate for the deficient UCL, it may not be able to overcome the tremendous valgus stress occurring across the medial elbow during the pitching mechanism. This could account in part for the poor results experienced in attempting rehabilitation alone in these athletes. INDICATIONS FOR OPERATIVE TREATMENT
Reconstruction is indicated for athletes participating in high-demand upper extremity sports such as baseball pitching, javelin throwing, and serving sports. Overhead athletes experiencing medial elbow pain or a sense of movement in the elbow with valgus loads during sports participation, with UCL laxity or rupture diagnosed on physical examination and confirmed by imaging studies, would be candidates for ligament reconstruction once conservative measures have failed. Patients should be forewarned of the lengthy recovery period following surgery, and their sports requirements and aspirations should be consistent with this significant investment in attempting to restore a highly specific elbow function. OPERATIVE TECHNIQUE
Treatment options for UCL insufficiency include repair of the acute ligament disruption or reconstruction using free autogenous tendon graft. Results of surgical repair have not been as encouraging as reconstru~tion.~ Indications for repair remain narrow and include an acute proximal avulsion where the tissue is of good quality and there is no calcification present in the ligament. This presentation is rare, however, and generally reconstruction is recommended because its success rate in retuming to competition is higher and the recovery time is nearly the same for the two procedure^.^
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The graft of choice in reconstruction of the UCL is the ipsilateral palmaris longus tendon. There appears to be minimal morbidity associated with its removal, although care must be taken to avoid damage to the adjacent median nerve. The strength characteristics of the graft are excellent with the ultimate strength four times that of the anterior bundle of the UCL.42As the palmaris longus is not present in all individuals, other graft sources merit consideration. Graft options besides the ipsilatera1 palmaris include the gracilis or semitendinosis tendons, contralateral palmaris longus tendon, the plantaris tendon, the lesser toe extensors, or a 5-mm strip of the Achilles or flexor carpi radialis tendons.
AUTHORS' PREFERRED METHOD
The preoperative evaluation in the throwing athlete with UCL injury often identifies intra-articular pathology, which needs to be evaluated and addressed when the ligament is reconstructed. Also, some athletes with suspected ligament laxity can have equivocal opening on valgus stress examination. For these reasons, we often evaluate the elbow arthroscopically in conjunction with the ligament reconstruction procedure. The patient is positioned supine. A pneumatic tourniquet is used for hemostasis. The arm is placed in the over-the-chest position and the hand is held by an assistant or secured with an arm holder, such as the McConnell device (McConnell Orthopaedic Manufacturing Co., Greenville, TX). Routine arthroscopy portals are used to evaluate the elbow. The arthroscopic evaluation permits visualization of the anterior and posterior compartments. The anterior compartment is evaluated for loose bodies and spur formation. The capitellum surface is visualized for reciprocal chondral lesions seen in acute or long-standing UCL deficiency and for osteochondritis dessicans (OCD) lesions. Although only the anteriormost 20% to 30% of the anterior bundle is visible from the anterior portal, medial elbow stability can be assessed at 51 If the diagnosis of UCL incompetence is unclear, an arthro~copy.'~, arthroscopic stress test for the UCL can be perf~rmed.'~ With the elbow at 90" of flexion, the forearm is pronated and valgus stress is applied. In the normal elbow a maximum of 1 to 2 mm of medial opening will be observed. If the UCL is incompetent, greater than 3 mm of opening between the coronoid and medial humerus is observed. The posterior compartment also is evaluated for loose bodies. These athletes often have a medial olecranon spur in association with the valgus extension overload experienced during throwing.58Debridement of the spur is accomplished easily at arthroscopy. The chondral surfaces of the posterior compartment also are evaluated at arthroscopy. We have seen a characteristic reciprocal chondral lesion of the medial christa of the posterior humeral trochlea occurring in association with the olecranon spurring in throwers with UCL insufficiency. For these reasons, we
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have found arthroscopy to be a valuable adjunct to the evaluation and treatment of UCL injuries. After completion of the arthroscopy, the arm is abducted and externally rotated and placed on an arm board for the reconstruction procedure. The ipsilateral palmaris longus tendon is the preferred graft. Its presence must be confirmed during the preoperative exam. Otherwise, one of the alternative free tendon grafts mentioned earlier must be used. We now use a small tendon stripper to harvest the tendon, with only a single incision at the distal palmar crease. The harvest is faster and easier than the traditional two-incision technique, and there has been no associated morbidity from bleeding or median nerve trauma in our experience. The tendon is identified first through a transverse 5- to 10-mm incision at the distal palmar crease of the wrist. The tendon is mobilized using gentle blunt dissection, taking care to avoid the underlying median nerve and its palmar cutaneous branch. The distal tendon is cut at its insertion at the palmar fascia and advanced out the proximal incision. It is transected at the musculotendinous junction, providing a graft of approximately 15 cm. One end of the graft is secured with a #1 braided nonabsorbable suture using a Krakow stitch. After completing the graft preparation, the elbow reconstruction is begun. The arm is exsanguinated and the tourniquet inflated. A 10-cm curvilinear incision is made over the medial epicondyle, from the distal third of the intramuscular septum across the medial epicondyle to a point 2 cm beyond the sublime tubercle of the ulna. The fascia and aponeurosis of the flexor pronator group are exposed carefully and the medial antebrachial cutaneous nerve is isolated and protected. The nerve crosses the field anywhere from 3 to 60 mm distal to the epicondyle (Fig. 4).45If a previous ulnar nerve transposition has taken place, the ulnar nerve should be isolated and protected. This emphasizes the need for a thorough preoperative history. Once the flexor pronator has been exposed, there are two options for exposure of the ligament. The standard approach as described by Jobe involved transecting the conjoined tendon of the flexor-pronator and reflecting it distally to gain exposure to the medial capsule.25This has proven a reliable technique for ligament exposure, but we prefer the less traumatic muscle-splitting appr0ach.4~ The interval for the muscle split is the fascia1 raphe between the ulnar innervated flexor carpi ulnaris and the median innervated flexor mass. Usually, this raphe is identified easily at the posterior one third of the flexor pronator group (Fig. 5). The fascia is incised longitudinally along the raphe from the medial epicondyle, extending distally 1 cm distal to the sublime tubercle of the ulna, identified using deep fingertip palpation through the flexor mass. The ulnar nerve lies just posterior to this interval and should be identified and protected before completing the muscle split. The muscle fibers are split longitudinally in line with the fibers, using blunt dissection to expose the medial joint capsule. This interval separates the flexor carpi ulnaris (medial) from the palmaris longus (lateral) in the superficial dihsection, and in the deeper dissection
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Figure 4. The safe interval through which the muscle splitting incision is performed. Care must be taken to protect the medial antebrachial cutaneous nerve. MCL = medial collateral ligament. (From Smith GR, Altchek DW, Pagnani MJ, et al: A muscle-splitting approach to the ulnar collateral ligament of the elbow: Neuroanatomy and operative technique. Am J Sports Med 24:575-580,1996; with permission.)
separates the flexor carpi ulnaris from the flexor digitorum superficialis.& Once on the capsule, exposure of the medial ulna distal to the sublime tubercle is done using subperiosteal dissection to avoid transecting motor branches to the flexor carpi ulnaris. Anatomic dissection data identifying the points of motor branch innervation from both the median and
Figure 5. The incision through the raphe of the flexor pronator mass.
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ulnar nerves was used in developing the approach to avoid denervation of the surrounding muscle.45 Blunt retractors are used to retract the anterior and posterior muscle masses, to access the capsule and ligament. The ligament then is incised longitudinally, exposing the medial joint, to assess for intra-articular pathology. A valgus stress is applied with the elbow flexed 30", 60", and 90" to assess the ligament (Fig. 6 ) . The joint will open 3 to 4 mm with a As much as possible of valgus stress when the ligament is ins~fficient.~ the ligament origin and insertion should be preserved. The ligament and capsule can be closed later, before graft tensioning, in a pant-over-vest imbrication to add support to the reconstruction. The entire anterior bundle is exposed from its origin to the insertion on the ulna. The subperiosteal dissection is continued distally approximately 1 cm on the ulna to allow for graft tunnel placement. The alternative exposure described by Jobe entails transecting the tendinous origin of the flexor pronator origin 1 cm distal to the medial epicondyle and reflecting the tendon and muscle distally.25Although it allows excellent exposure to the ligament, this approach is more time consuming and more traumatic to the tissues. The authors prefer the muscle-splitting approach for its ease of exposure, low risk of muscle denervation, and potentially lower postoperative morbidity. If preoperative work-up indicates ulnar neuropathy, anterior transposition can be achieved easily through the muscle-splitting approach. The authors prefer a subfascial transposition. If a submuscular transposition is the sur-
Figure 6. The muscle splitting approach to the ulnar collateral ligament demonstrates the insertion of the anterior bundle on the sublime tubercle of the ulna.
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geon's preferred technique, the flexor pronator turndown would be the best approach for combining these procedures. Care must be taken to preserve the motor branches to the flexor carpi ulnaris. Graft fixation is achieved through bone tunnels in the ulna and medial epicondyle. Standard ulnar tunnels are created with convergent drill holes at the anterior and posterior margins of the sublime tubercle of the ulna separated by a 1 to 2-cm bone bridge.25The hard cortical surface of the tubercle provides an excellent bone bridge for graft fixation. Drill holes can be made using a 3.2-mm drill or a small #3 burr. The holes are connected under the bridge using small curved curette, taking care to preserve the bone bridge. For graft fixation in the medial epicondyle, Jobe originally described fashioning divergent drill holes from a single entry hole on the anterior distal e p i c ~ n d y l eWe . ~ ~have developed a technique of counter-sinking the proximal ends of the graft into a single unicortical drill hole at the same anterior distal origin of the anterior bundle and tensioning the graft over bone bridge sutures on the proximal epicondyle. Our technique uses a 3.2-mm drill or small #4 burr to create a 15mm cylindrical unicortical tunnel in the medial epicondyle preserving the proximal anterior cortex of the epicondyle. Two small 2.0-mm divergent drill holes, separated by 5 to 10 mm, are placed through the proximal anterior cortex of the medial epicondyle entering into the cylindrical graft docking tunnel (Fig. 7). A suture passer is used from each of the two upper humeral tunnels to pass a looped suture to be used later for graft passage. With the elbow reduced, the horizontal incision in the UCL is repaired using a 2-0 absorbable suture. The graft is passed through the ulnar tunnel, generally from anterior to posterior (Fig. 8). The limb of the graft that has sutures already placed is then passed into the humeral tunnel with the sutures pulled exiting one the small superior humeral tunnels. With this first limb of the graft securely docked in the humerus, the elbow is reduced with maximal forearm supination and gentle varus stress. While tension is maintained on the graft, the elbow is ranged from flexion to extension to eliminate potential creep in the graft. The final length of the graft then is measured by placing the free limb of the graft adjacent to the humeral tunnel and visually estimating the length of the graft that will allow the graft to be tensioned in the humeral tunnel. This point is marked with dye and a #1 braided nonabsorbable suture is placed in a Krackow fashion in the free end of the graft (Fig. 9). This end of the graft then is docked securely in the humeral tunnel with the sutures exiting the small superior humeral tunnel. Final graft tensioning is performed by again placing the elbow through a full range of motion with varus stress placed on the elbow. Once the surgeon is satisfied with the graft tension and isometry, the two sets of graft sutures are tied over the bone bridge on the humeral epicondyle (Fig. 10). The range of motion of the elbow is checked to assess final ligament isometry and a gentle valgus stress is applied in 60" of flexion to assess graft tension. The tourniquet is released, hemostasis is achieved, and the wound is irrigated copiously. We have not found the
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Figure 7. Convergent drill holes in the ulna anterior and posterior to the sublime tubercle with approximately 1-cm bone bridge. Divergent drill holes in the medial epicondyle.
need to drain the wound when the muscle-splitting technique is used. Closure for the muscle-splitting technique is simple. The fascia1 split is closed using interrupted #2-0 absorbable sutures. The skin is closed routinely with subcuticular suture. The arm is then placed in a bulky, light-compression splint with the arm in approximately 60" of flexion.. Using the divergent tunnel technique described by Jobe, the graft is advanced into one tunnel, around the epicondyle, and back through the second tunnel in a figure-of-eight fashi0n.2~The graft is tensioned and secured to itself. The authors prefer the unicortical tunnel technique for its ease of graft tensioning and secure bone bridge fixation. Care must be taken to fashion the tunnel in a cylindrical shape not conical) to allow the graft to countersink adequately into the tunnel during tensioning. The graft also must be cut precisely to allow adequate countersinking in the tunnel for bony ingrowth without making it too long, such that it cannot be tensioned in the confines of the tunnel. POSTOPERATIVE MANAGEMENT
The importance of a systematic rehabilitation program cannot be overemphasized. Close cooperation between the supervising surgeon,
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Figure 8. The graft is passed by advancing end with Krackow suture from anterior to posterior through the ulnar tunnel.
Figure 9. The ends of the tendons are inserted into the unicortical drill hole and the graft is countersunk into the tunnel and tensioned
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Figure 10. With the medial joint closed, the sutures are tied over the bone bridge.
therapist, athletic trainer, coaches, and athlete is essential. The authors currently use a six-phase progressive rehabilitation program on throwers after UCL reconstruction before beginning the graduated throwing phase of recovery. Phase 1is the first week postoperatively. The arm is immobilized in 60" of flexion. Gripping exercises are initiated with wrist range of motion and therapeutic modalities as needed. Phase 2 consists of weeks 1 to 4.The splint is removed at 1 week and a hinged elbow brace is applied under the surgeon's supervision. Range of motion of 40" to 90" allowed. Wrist and elbow isometrics are initiated. Shoulder isometrics, excluding internal and external rotation, also are begun. Manual scapular stabilization exercises are begun, and therapeutic modalities as needed. In phase 3 (4 to 6 weeks), the brace is opened to 20" to 110" at 5 weeks under the surgeon's supervision. Range of motion is increased gradually and light wrist and elbow isotonics are begun. Scapular and shoulder strengthening are advanced. Shoulder external rotation is avoided in an effort to avoid valgus stress to the elbow. Phase 4 consists of weeks 6 to 8. The brace is removed at 6 weeks under the surgeon's supervision. Wrist, elbow, and shoulder isotonics are progressed and external rotation in neutral shoulder abduction is initiated. Upper-body ergonometric exercises are begun. In phase 5 (8 to 10 weeks), wrist and elbow strengthening is advanced, stressing eccentrics. Aggressive shoulder strengthening is begun,
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including overhead rotator cuff exercises. Upper-body ergonometric endurance training is advanced and throwing patterns are begun. In phase 6 (10 to 13 weeks), aggressive upper-body strengthening is continued and plyometric training is initiated. Endurance training is continued and restoration of normal flexibility is emphasized. After completing this initial rehabilitation, interval throwing is initiated under the surgeon’s supervision and advanced between weeks 14 and 20. Light tossing, 30 to 40 feet, without a wind-up is begun, with two to three sessions a week for 10 to 15 minutes each. At 5 months, the distance is increased to 60 feet; at 6 months, an easy wind-up is added. Flexibility exercises are continued, and a total upper-body exercise program using the normal training principles is started. Ice is used after each training or throwing session to reduce inflammation. At 7 to 8 months, pitchers can return to the mound. The duration of the throwing sessions is increased to 25 minutes and effort progresses to 70% velocity during the eighth or ninth month. During the following 2 months, attention is focused on body mechanics and technique. Throwing sessions are lengthened and game simulation is begun. Competitive throwing is permitted at 9 months if upper-body range of motion and strength are normal and if the arm is pain free. Elite level pitchers may require 18 months to regain full preoperative proprioception, rhythm, and accuracyz5 RESULTS
Most overhead athletes undergoing UCL reconstruction are able to return to their previous level of function. In our series of 30 baseball players with 2-year follow-up, 29 of 30 (97%)have returned to their preinjury level of competition.2Another cohort of 33 patients with a minimum of 2-year follow-up demonstrated 93% excellent results in the subset of patients that were highly competitive athletes who had not had a prior surgical procedure.50In one series, 68% of overhead athletes (most of whom were baseball players) were able to return to their previous level of participati~n.~~ In this series, 50% of the repair group returned to their previous level. The time to recovery differed between the two groups, with the repair group averaging 9 months to return and the reconstruction group averaging 12 months. Those with previous operations on the elbow were shown to have a lower chance of returning to their previous level of participation. Of the various sport participants undergoing UCL reconstruction, baseball pitchers are the most difficult to return to their previous level of function. COMPLICATIONS
The most common postoperative complications following UCL reconstruction include trauma to the medial antebrachial cutaneous or
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
43
ulnar nerves. In the authors’ series of 30 throwers at 2 years postoperatively, one patient required resection of a neuroma of the medial antebrachial cutaneous nerve and subsequently was diagnosed with reflex sympathetic dystrophy. The second complication occurred in a high school catcher who, while hitting at 7 months postoperatively, suffered a fracture of the ulnar tunnel.* This patient underwent successful revision reconstruction and has returned to high school baseball. Thompson et a1 reported on 83 reconstructions, in which 5% demonstrated transient ulnar nerve symptoms.50All neurologic symptoms in this group resolved with conservative management. Ulnar nerve irritation was noted in 21% of reconstructions in one series? Seven patients who had ulnar nerve transpositions with the primary reconstruction required a revision ulnar nerve procedure. We do not routinely transpose or release the ulnar nerve using the muscle-splitting approach and find most cases do not require ulnar nerve procedures. When the ulnar nerve is addressed, gentle handling and preservation of its vascular supply is essential. Meticulous hemostasis can prevent postoperative hematoma formation. We routinely address intra-articular pathology, such as loose bodies or osteophytes, with preliminary arthroscopy to avoid the need for a posterior arthrotomy near the ulnar nerve. Careful dissection during the approach to identify and protect the cutaneous nerves can prevent formation of painful neuromas. References 1. Albright JA, Jokl P, Shaw R, et al: Clinical study of baseball pitchers: Correlation of injury to the throwing arm with method of delivery. Am J Sports Med 6:15-21, 1978 2. Altchek D, Hyman JL, Williams RJ, et al: Ulnar Collateral Ligament Reconstruction in Throwers Using the “Docking” Technique: Two-Year Results. Sun Valley, ID, American Orthopaedic Association, 1999 3. Andrews JR, Timmerman LA: Outcome of elbow surgery in professional baseball players. Am J Sports Med 23:407413, 1995 4. Andrews JR, Whiteside JA: Common elbow problems in the athlete. J Orthop Sports Phys Ther 17289-295, 1993 5. Barnes DA, Tullos HS: An analysis of 100 symptomatic baseball players. Am J Sports Med 6:62-67,1978 6 . Barrentine SW, Fleisig GS, Whiteside JA, et al: Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow. J Orthop Sports Phys Ther 28:405415, 1998 7. Callaway GH, Field LD, Deng XH, et a1 Biomechanical evaluation of the medial collateral ligament of the elbow. J Bone Joint Surg Am 79:1223-1231, 1997 8. Ciccotti MG, Jobe Ew: Medial collateral ligament instability and ulnar neuritis in the athlete’s elbow. Instr Course Lect 48:383-391, 1999 9. Conway JE, Jobe FW,Glousman RE, et al. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 7467-83, 1992 10. Davidson PA, Pink M, Perry J, et al: Functional anatomy of the flexor pronator muscle group in relation to the medial collateral ligament of the elbow. Am J Sports Med 23245-250, 1995 11. Dillman CJ, Fleisig GS, Andrews J R Biomechanics of pitching with emphasis upon shoulder kinematics. J Orthop Sports Phys Ther 18:402-408, 1993 12. Elattrache NS,
McMahon PJ: Dislocations and collateral ligament injuries. In Hemdon, JH: Surgery Reconstruction of the Upper Extremity. Stamford, Appleton and Lange, 1999, pp 321331 13. Ellenbecker TS,Mattalino AJ, E l m EA, et a1 Medial elbow joint laxity in professional baseball pitchers. A bilateral comparison using stress radiography. Am J Sports Med 26420424,1998 14. Field LD, Altchek DW Elbow injuries. Clin Sports Med 1459-78,1995 15. Field LD, Altchek DW Evaluation of the arthroscopic valgus instability test of the elbow. Am J Sports Med 24377-181,1996 16. Field LD, Savoie FH: Common elbow injuries in sport. Sports Med 26:193-205, 1998 17. Fleisig GS, Andrews JR, Dillman CJ, et al: Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med 23:233-239, 1995 18. Floris S, Olsen BS, Dalstra M, et al.: The medial collateral ligament of the elbow joint: Anatomy and kinematics. J Shoulder Elbow Surg 7 3 5 3 5 1 , 1 9 9 8 19. Glousman RE, Barron J, Jobe FW, et al: An electromyographic analysis of the elbow in normal and injured pitchers with medial collateral ligament insufficiency. Am J Sports Med 20311-317, 1992 20. Hamilton CD, Glousman RE, Jobe FW, et a1 Dynamic stability of the elbow: Electromyographic analysis of the flexor pronator group and the extensor group in pitchers with valgus instability. J Shoulder Elbow Surg 5347-354, 1996 21. Hechtman KS, Tjin ATEW, Zvijac JE,et al: Biomechanics of a less invasive procedure for reconstruction of the ulnar collateral ligament of the elbow. Am J Sports Med 26620424,1998 22. Hotchkiss RN, Weiland AJ: Valgus stability of the elbow. J Orthop Res 5: 372-377,1987 23. Jobe FW, Elattrache N S Diagnosis and treatment of ulnar collateral ligament injuries in athletes. In Morrey B F The Elbow and Its Disorders. Philadelphia, WB Saunders, 1993, pp 566-572 24. Jobe FW, Elattrache N S Treatment of ulnar collateral ligament injuries in athletes. In Morrey B F Master Techniques in Orthopedic Surgery: The Elbow. New York, Raven Press, 1994, pp 149-168 25. Jobe FW, Stark H, Lombard0 SJ: Reconstruction of the ulnar collateral ligament in athletes. J Bone Joint Surg Am 68:1158-1163, 1986 26. Johnston J, Plancher KD, Hawkins RJ: Elbow injuries to the throwing athlete. Clin Sports Med 15:307-329, 1996 27. King J, Brelsford HJ, Tullos H S Analysis of the pitching arm of the professional baseball pitcher. Clin Orthop 67116-123, 1969 28. Lee GA, Katz SD, Lazarus M D Elbow valgus stress radiography in an uninjured population. Am J Sports Med 26:425-427, 1998 29. Lee ML, Rosenwasser MP: Chronic elbow instability. Orthop Clin North Am 30:8189,1999 30. London JT: Kinematics of the elbow. J Bone Joint Surg Am 63:529-535,1981 31. Mirowitz SA, London SL Ulnar collateral ligament injury in baseball pitchers: MR imaging evaluation. Radiology 185:573-576, 1992 32. Morrey B F Applied anatomy and biomechanics of the elbow joint. Instr Course Lect 35:59-68, 1986 33. Morrey BF, An KN: Articular and ligamentous contributions to the stability of the elbow joint. Am J Sports Med 11:315-319, 1983 34. Morrey BF, An KN: Functional anatomy of the ligaments of the elbow. Clin Orthrop 201:84-90, 1985 35. Morrey BF, Chao EY Passive motion of the elbow joint. J Bone Joint Surg Am 58:501-508, 1976 36. Morrey BF, Tanaka S, An KN: Valgus stability of the elbow. A definition of primary and secondary constraints. Clin Orthop 26537-195,1991 37. Nakanishi K, Masatomi T, Ochi T, et al: MR arthrography of elbow: Evaluation of the ulnar collateral ligament of elbow. Skeletal Radio1 25:629-634, 1996 38. Norwood LA, Shook JA, Andrews J R Acute medial elbow ruptures. Am J Sports Med 9%-19, 1981 39. Ochi N, Ogura T, Hashizume H, et a1 Anatomic relation between the medial collateral
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40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53.
54. 55. 56. 57. 58. 59.
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ligament of the elbow and the humero-ulnar joint axis. J Shoulder Elbow Surg 8610, 1999 ODriscoll SW, Jaloszynski R, Morrey BF, et al: Origin of the medial ulnar collateral ligament. J Hand Surg [Am] 17164-168,1992 Protzman Rl? Dislocation of the elbow joint. J Bone Joint Surg Am 60:539-541, 1978 Regan WD, Korinek SL, Morrey BF, et a1 Biomechanical study of ligaments around the elbow joint. C l i Orthop 271:170-179, 1991 Schwab GH, Bennett JB, Woods GW, et al: Biomechanics of elbow instability: The role of the medial collateral ligament. Clin Orthop 146:42-52, 1980 Schwartz ML, al-Zahrani S, Morwessel RM, et al: Ulnar collateral ligament injury in the throwing athlete: Evaluation with saline-enhanced MR arthrography. Radiology 197297-299, 1995 Smith GR, Altchek DW, Pagnani MJ, et al: A muscle-splitting approach to the ulnar collateral ligament of the elbow. Neuroanatomy and operative technique. Am J Sports Med 24575580,1996 Sojbjerg JO, Ovesen J, Nielsen S: Experimental elbow instability after transection of the medial collateral ligament. Clin Orthop 218:186-190, 1987 Sugimoto H, Ohsawa T: Ulnar collateral ligament in the growing elbow: MR imaging of normal development and throwing injuries. Radiology 192:417422, 1994 Suzuki K, Minami A, Suenaga N, et al: Oblique stress fracture of the olecranon in baseball pitchers. J Shoulder Elbow Surg 6:491494, 1997 Tan F, Lomasney LM, Demos TC: Radiologic case study. Ulnar collateral ligament injury. Orthopedics 21:827, 819-823, 1998 Thompson WH, Jobe FW, Yocum L A Ulnar collateral ligament reconstruction in throwing athletes: Muscle splitting approach without transposition of the ulnar nerve [abstract]. J Shoulder Elbow Surg 7175, 1998 Timmerman LA, Andrews JR Histology and arthroscopic anatomy of the ulnar collateral ligament of the elbow. Am J Sports Med 22667473,1994 Timmerman LA, Andrews J R Undersurface tear of the ulnar collateral ligament in baseball players. A newly recognized lesion. Am J Sports Med 22:33-36, 1994 Timmerman LA, Schwartz ML, Andrews J R Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med 22:26-31 [discussion, 321, 1994 Tullos HS, King JW: Throwing mechanism in sports. Orthop Clin North Am 4: 709720, 1973 Tullos HS, Schwab G, Bennett JB, et al: Factors influencing elbow instability. Instr Course Lect 30:185-199, 1981 Veltri DM, OBrien SJ, Field LD, et al: The milking manuever: A new test to evaluate the MCL of the elbow in the throwing athlete. J Shoulder Elbow Surg 4520, 22, 1995 Werner SL, Fleisig GS, Dillman CJ, et al: Biomechanics of the elbow during baseball pitching. J Orthop Sports Phys Ther 17276278,1993 Wilson FD, Andrews JR, Blackbum, TA, et al: Valgus extension overload in the pitching elbow. Am J Sports Med 11:83-88, 1983 Xue 0,Masuda K A biomechanical study of fast throwing movements of the shoulder in baseball pitching. Chin Med J (Engl) 110:220-224, 1997
Address reprint requests to David W. Altchek, MD Sports Medicine and Shoulder Service The Hospital for Special Surgery Cornell University Medical Center 535 East 70th Street New York, NY 10021
0278-5919/01 $15.00
+ .OO
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES Jon Hyman, MD, Nathan M. Breazeale, MD, and David W. Altchek, MD,
Valgus instability of the elbow is uncommon in the general population and is not seen often in most athletes. Individuals who throw repeatedly, especially baseball pitchers, represent most of these exceptional cases where valgus instability can be identified. The extreme valgus loads generated by the throwing motion place tremendous tensile stress across the medial elbow joint and the ligaments that stabilize it. These forces peak at the medial elbow during late cocking and early acceleration phases of throwing, as the elbow moves from flexion to extension at speeds that have been estimated to reach 3000 deg/sec." The load produced during a typical fastball thrown by an elite pitcher has been estimated to approach the tensile strength of the medial collateral ligament," confirming the notion that pitching is a high-risk activity for the medial collateral ligament. Subtle injury to the ulnar collateral ligament can lead to disabling instability in the throwing athlete in the setting of repetitive valgus stress.4,9, 25, 32, 38, 41, 52,58 When instability prevents return to competition in the overhead athlete, surgical reconstruction often is indicated. Valgus instability can be detected at a much lower incidence in javelin throwers, tennis players, or trauma. Complete ulnar collateral ligament injuries are rare in racquet sports, but repetitive valgus overload can lead To recurrent episodes of microtrauma and subsequent symptomatic valgus in~tabi1ity.l~ Elbow dislocation can rupture the ulnar
From the Sports Medicine and Shoulder Service, The Hospital for Special Surgery, Comell University Medical Center, New York, New York (JH, DWA); and Private Practice, Austin, Texas (NMB) CLINICS IN SPORTS MEDICINE VOLUME 20 * NUMBER 1 'JANUARY 2001
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collateral ligament or avulse it from the medial epicondyle.12Recurrent instability after a simple elbow dislocation is rare. Acute instability generally is not seen if the flexor-pronator muscle group remains intact.55 CLINICAL ANATOMY
A thorough understanding of the anatomy and biomechanics of the elbow are essential in diagnosing and treating injuries of the elbow ulnar collateral ligament (UCL).34, 51 The UCL consists of an anterior bundle, a posterior bundle, and transverse fibers (Fig. 1).The anterior bundle has been shown to be the primary restraint to valgus stress at 30°, 60°,and 90" of elbow fle~ion.~, 22, 32-34* 42, 46, 55 The anterior bundle of the UCL is the most discernible of the three portions of the ligament complex. Its margins are readily distinguished from the surrounding joint capsule and its fibers often are associated intimately with the deep surface of the flexor mass.M,51 The posterior bundle consists of a less distinct fan-shaped thickening of the posterior capsule.MThe transverse fibers originate and insert on the ulna, covering a bony depression on the medial portion of the trochlear notch, and contribute little or nothing to the stability of the elbow. The anterior bundle is the most important portion of the complex when treating valgus instability of the elbow. The ligament originates from the anterior inferior surface of the medial epicondyle. The width of the origin varies but in most cases occupies the middle two thirds to three quarters of the epicondyle in the coronal plane40 (Fig. 2). A small space remains between the lateral edge of the ligament and the medial crista of the trochlea, allowing for a synovial reflection in the joint, 367
Posterior bundle Transverse ligament Figure 1. The anterior bundle of the ulnar collateral ligament is the primary stabilizer of the elbow-resistingvalgus stress. (From Jobe FW, Elattrache NS: Diagnosis and treatment of ulnar collateral ligament injuries in athletes. In Morrey BF (ed): The Elbow and Its Disorders. Philadelphia,WB Saunders, 1993.)
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
k
27
-I
L ‘E
13% 67% 20%
Figure 2. The anterior part of the medial epicondyle removed by orthogonal osteotomies. On the right a 2 mm thick slice through the widest portion of the origin of the anterior bundle of the ulnar collateral ligament. (From O’Driscoll SW, Jobszynski R, Morrey BF, et at: Origin of the medial ulnar cokateral ligament. J Hand Surg [Am] 17:164-168, 1992; with permission.)
readily visualized on MRI. Morrey and An found the mean length of the anterior bundle to be 27.1 ? 4.3 mm and the mean width to be 4.7 k 1.2 mm.34The anterior bundle inserts on the medial border of the coronoid at the sublime tubercle.34,51 Timmerman and Andrews have defined the histology and arthroscopic anatomy of the anterior bundle.51The medial capsule consists of a synovial lining with two distinct capsular layers between which pass the anterior and posterior bundles.51The anterior bundle consists of welldefined collagen bundles in parallel arrangement typical of ligaments. In cross section, the bundle consists of two portions: one layer between the two synovial layers of the joint capsule, and a second layer superficial to the capsule blending with the deep surface of the flexor mass. The posterior bundle consists of a smaller area of collagen in the capsular layers. FUNCTIONAL ANATOMY
Understanding the functional anatomy of the ulnar collateral ligament requires a synthesis of the kinematics of elbow motion with the biomechanics of the throwing mechanism. The ulnohumeral joint is a hinge or ginglymus joint permitting flexion and extension. The articulation between the greater sigmoid notch of the olecranon and the humeral trochlea is one of the most congruous and constrained joints in the body.
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With loading, the elbow flexors and extensors tend to seat the olecranon in the humeral trochlea, contributing valgus stability under dynamic conditions. Biomechanical studies on the loaded and unloaded cadaveric elbow by Morrey et a1 demonstrated decreased valgus laxity against a gravity valgus stress in the loaded specimens compared to the unloaded specimens both before and after sectioning the anterior bundle of the ulnar collateral ligament.36 The anterior bundle of the ulnar collateral ligament has been shown to be the primary restraint to valgus stress and the radial head a secondary restraint.=,36, 46 With anterior bundle sectioning, the resultant instability is greatest between 60" to 70" and least at full extension and full flexion.& The flexion-extension axis or center of rotation of the elbow lies in the center of the trochlea and capitellum as viewed from the lateral projection.30,35 The origin of the anterior bundle of the ulnar collateral ligament lies slightly posterior to the rotational center of the elbow. The anterior bundle is divided further into an anterior band and a posterior band.43The eccentric origin of these components of the anterior bundle in relation to the rotational center through the trochlea creates a cam effect during flexion and extension. The anterior band tightens during extension and the posterior band tightens during flexion. This reciprocal tightening of the two functional components of the anterior bundle allows the ligament to remain taut throughout the full range of flexion despite its eccentric origin in relation to the rotational center of the BIOMECHANICS OF THROWING
Rupture of the ulnar collateral ligament in athletes has been documented in several sports, but most cases occur in throwing athlete^.^, ~ 5 , 27, 54 An understanding of the throwing mechanism and its relationship to injury is essential in treating ulnar collateral ligament tears. The transition from the late cocking phase to early acceleration places extreme valgus stress on the medial structures of the e1b0w.I~The anterior bundle of the UCL receives the greatest tensile stress as the primary restraint.22,36, 46 Laterally, the radial head is a secondary restraint to the valgus load and receives significant compressive and shear stresses.22, 36, 46 It has been estimated that between 100 and 120 Nm of varus torque is required to resist the valgus stress produced by the throwing motion in elite level Electromyographic data on throwers with normal elbows and those with UCL instability show that the muscles positioned to function as dynamic stabilizers of the medial elbow, specifically the flexor carpi radialis, pronator teres, and flexor carpi ulnaris, do not appear to compensate for UCL laxity and in fact showed slightly decreased activity in the UCL-insufficient pitchers during thr~wing.'~, 56 This suggests there is limited ability for dynamic stabilization of the medially unstable elbow in high-demand throwers.
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
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HISTORY
A detailed history and physical examination is essential in evaluating the elbow for UCL insufficiency. Most athletes presenting for evaluation are involved in repetitive overhead activities. Knowledge of previous elbow injuries and treatments is important in the initial work-up. The chronology of the development of elbow pain can give clues to the underlying pathology and indicate the injury's severity. A history of mild pain following a return to overhead activities or a significant increase in activity intensity or duration suggests an overuse syndrome. This generally responds to conservative measures directed at the inflammatory response following overuse. These athletes often are able to continue throwing at 100% but develop pain after use. Medial elbow pain with throwing beyond 60% to 75% effort can suggest ligament attenuation.', 5, 54 These athletes often have a history of recurrent medial elbow injury and can sense "movement" or crepitation in the elbow when attempting to throw beyond 75%. In long-standing cases of UCL insufficiency, the athlete can experience mechanical symptoms, such as locking and catching, suggestive of loose bodies or early degenerative changes in the joint. Some throwers report radiating paresthesias into the ulnar fourth and fifth digits. In contrast to this gradual development of UCL insufficiency, some athletes with or without previous elbow symptoms can experience an acute rupture of the ligament. They often will complain of a sudden, sharp pain over the medial elbow. They often can identify the exact moment or pitch that symptoms developed and can experience a "pop" at the moment of ligament rupture. Medial elbow opening with valgus stress can cause ulnar nerve stretching with paresthesias radiating into the medial forearm, hand, and 4th and 5th digits. The pitcher sometimes is able to continue throwing, often with an alteration in throwing mechanics, but is not able to exceed a 75% effort. PHYSICAL EXAMINATION
Physical examination of the elbow for UCL injury entails assessing the integrity of the ligament and evaluating the joint and surrounding structures for associated injuries. Inspection of the upper extremity in overhead athletes often reveals hemihypertrophy of the dominant ext ~ e m i t yElbow . ~ ~ range of motion can be limited by pain or guarding in acute cases. In chronic cases, especially in throwers, motion can be limited at terminal extension due to bony changes in the posterior compartment, capsular contracture, or loose bodies in the olecranon fossa. Crepitance with motion suggests the presence of loose bodies or degenerative changes in the joint. Palpation over the ligament usually elicits tenderness along its course when acute injury is present. The ligament originates at the distal
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anterior portion of the medial epicondyle of the humerus and inserts on the sublime tubercle or medial eminence near the coronoid process.40,51 Pain at the ligament origin can mimic medial epicondylitis or in extreme injury, rupture of the flexor-pronator origin. Pain from the conjoined tendon usually can be elicited with resisted wrist flexion, resisted forearm pronation, or a firm fist clench, differentiating this clinical entity from UCL injury. Injury to the insertion of the UCL is well distal to the medial epicondyle and is differentiated by location of the point tenderness. Identification and palpation of the ligament can be facilitated by using the "milking maneuver."56During examination, the patient places the opposite hand under the elbow to grasp the thumb of the affected arm. With the injured elbow flexed greater than 90" a valgus stress is applied to the elbow by pulling on the thumb. This hyperflexion tends to isolate the anterior bundle of the UCL and the valgus stress places the anterior bundle on stretch. Positioning the elbow in this fashion facilitates location and palpation of the tensioned ligament under the mass of the flexor-pronator origin. Positioning for the maneuver alone can elicit pain over the medial elbow as the anterior bundle is placed on stretch. Valgus stability of the elbow is best examined with the elbow positioned in approximately 90" of flexion, freeing the olecranon tip from the fossa p~steriorly.~ Forearm pronation and wrist flexion relax the flexor-pronator mass, allowing isolation of the UCL. The pronated hand can be held in one of the examiner's hands, or alternatively between the examiner's trunk and arm, while the examiner's other hand is placed on the lateral side of the elbow and a valgus stress is applied to the arm. The ligament is palpated for tenderness during application of the valgus stress. The degree of joint opening and quality of the ligament end point also are assessed with the maneuver, and the affected arm is compared to the asymptomatic side. Even with complete ligament rupture, the side-to-side difference in joint opening can be only 3 to 4 mm and the end point feel can be subtle, making the maneuver difficult to master. We recommend a variation of the stress test to aid in sensing the degree of medial joint opening. After applying valgus stress and palpating the end point, place a varus stress on the elbow. It is often easier to sense the amount of joint opening by the extent of joint line closure in moving from the valgus to varus stress. The end point palpated with a varus stress as the ulno-humeral articulation closes is firm and discrete, and can assist the examiner in determining the amount of medial joint laxity. Complete examination of the elbow with suspected UCL injury requires assessment of other medial elbow structures. Ulnar nerve irritation can be mistaken for ligament injury or can occur in conjunction with it. Bony hypertrophy, medial joint spurring, or inflammation associated with UCL injury can compress the ulnar nerve in the cubital tunnel. Nerve subluxation, especially during the late cocking throwing phase, can lead to medial elbow pain. Careful neurologic examination is essen-
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
31
tial in the work-up to rule out isolated or associated ulnar nerve pathology. Examination of the nerve should focus on nerve sensitivity and tenderness, presence of a Tinel's sign, and distal sensory and motor function. Nerve stability also should be assessed, looking for hypermobility or anterior subluxation. Nerve involvement associated with UCL incompetence can require transposition in conjunction with ligament reconstruction. Valgus extension overload associated with throwing can lead to several well-recognized bony changes across the posteromedial Olecranon tip spurring and osteophyte formation, along with bony hypertrophy of the olecranon fossa and loose body formation, can lead to impingement of the olecranon tip in the fossa at terminal extension, especially in throwing athletes. Pain is elicited with snapping extension of the elbow. Chondral injury and degenerative changes of the posterior joint also can create medial elbow pain similar to that experienced with UCL tears. Application of a valgus stress with the elbow in extension can reproduce pain in cases of posteromedial pain. All sources of medial elbow pain must be explored and any concurrent pathology must be addressed at surgery for a successful outcome in UCL reconstruction. IMAGING STUDIES
Radiographic evaluation is helpful in evaluating the elbow for ligament injury. Plain radiographs can identity degenerative changes and loose bodies in the elbow. Chronic UCL injury can cause calcification along the course of the ligament and medial joint line spurring. The posteromedial osteophyte is seen easily on the anteroposterior view and the hyperflexion lateral view of the elbow as the tip of the olecranon is advanced out of the fossa. Secondary degenerative changes also can be seen at the radiocapitellar joint and at the ulno-humeral joint in longstanding UCL insufficiency. Stress radiographs can be useful in the work-up but have been shown to be negative in known cases of UCL rupture.u, 24 Computed tomographic (CT) arthrography can be helpful in diagnosing an undersurface tear of the ligament.52,53 Extracapsular contrast extravasation with CT arthrography is seen with complete UCL tears. In a study of preoperative assessment of the UCL using CT arthrography and MR imaging (MRI), specificities were 91% and 100%, re~pectively.~~ MR imaging become the study of choice in evaluating the elbow with suspected UCL injury. Integrity of the ligament and associated injuries are readily seen. With the elbow in extension, the anterior bundle is well visualized on coronal section (Fig. 3), allowing differentiation of proximal, distal, or midsubstance ligament tears. MR imaging also allows evaluation of the articular surfaces and adjacent neuromuscular structures for any abnormalities identified on physical examination or radiographic evaluation. MR imaging also can be used postoperatively to evaluate graft integrity, placement, or reinjury. Because of the small
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Figure 3. Coronal gradient recoiled MR image of the left elbow demonstrates the anterior bundle of the medial ulnar collateral ligament. (Courtesy of Hollis G. Potter, MD, New York, NY.)
size of the ligament, technical considerations such as arm positioning, signal-to-noise ratio, and signal sequencing are important in producing an optimal image.31At our institution, MR imaging is performed using a 1.5-T scanner and elbow coil with 3-mm coronal sections through the medial collateral ligament (MCL).Our experience has demonstrated that the addition of intra-articular contrast agents (e.g., gadolinium) is not necessary to detect tears of the MCL. Because many tears are incomplete and therefore the leaking of contrast agent would not be seen. NONOPERATIVE TREATMENT
Treatment options for UCL injuries vary according to the severity of the injury and the patient's athletic requirements. For ligament strains, the basic principles for any ligament injury apply: cold and heat therapy, rest, nonsteroidal anti-inflammatory agents, range-of-motion exercises, therapeutic modalities, strengthening, and a gradual return to sport participation. For overhead athletes, a multidisciplinary approach to recovery is used, including the athletic trainer, therapists, coaches, and physician. Special attention to sport technique, especially with pitchers, should be used to avoid technical errors that place excessive valgus stress on the medial elbow.' Temporarily changing playing position to one that is less throwing intensive can aid the recovery process. Many nonpitchers with chronic UCL laxity can adapt their throwing technique to minimize valgus stress and remain active. Pitchers with laxity tend to
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
33
develop symptoms with repetitive attempts at throwing beyond 75% effort. As with chronic UCL laxity, acute ligament rupture in nonthrowers can be managed conservatively. Nonthrowing athletes rarely have significant pain or dysfunction once the initial inflammatory phase resolves, and the athlete can return gradually to most sports. Valgus-loading upper extremity maneuvers (e.g., javelin throwing, volleyball or tennis serving), and baseball throwing) do not respond as well to conservative treatment and often require surgery to return to preinjury level of function. Rehabilitation of symptomatic UCL laxity or complete ligament rupture has had poor results in returning these high-demand athletes to their previous level of function. Electromyographic analysis in UCL-deficient throwers showed a paradoxical inhibition of muscle recruitment of the flexor-pronator mass during throwing compared to normal throwing elbows.19,2o This could imply that, despite this muscle group’s ideal orientation to compensate for the deficient UCL, it may not be able to overcome the tremendous valgus stress occurring across the medial elbow during the pitching mechanism. This could account in part for the poor results experienced in attempting rehabilitation alone in these athletes. INDICATIONS FOR OPERATIVE TREATMENT
Reconstruction is indicated for athletes participating in high-demand upper extremity sports such as baseball pitching, javelin throwing, and serving sports. Overhead athletes experiencing medial elbow pain or a sense of movement in the elbow with valgus loads during sports participation, with UCL laxity or rupture diagnosed on physical examination and confirmed by imaging studies, would be candidates for ligament reconstruction once conservative measures have failed. Patients should be forewarned of the lengthy recovery period following surgery, and their sports requirements and aspirations should be consistent with this significant investment in attempting to restore a highly specific elbow function. OPERATIVE TECHNIQUE
Treatment options for UCL insufficiency include repair of the acute ligament disruption or reconstruction using free autogenous tendon graft. Results of surgical repair have not been as encouraging as reconstru~tion.~ Indications for repair remain narrow and include an acute proximal avulsion where the tissue is of good quality and there is no calcification present in the ligament. This presentation is rare, however, and generally reconstruction is recommended because its success rate in retuming to competition is higher and the recovery time is nearly the same for the two procedure^.^
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The graft of choice in reconstruction of the UCL is the ipsilateral palmaris longus tendon. There appears to be minimal morbidity associated with its removal, although care must be taken to avoid damage to the adjacent median nerve. The strength characteristics of the graft are excellent with the ultimate strength four times that of the anterior bundle of the UCL.42As the palmaris longus is not present in all individuals, other graft sources merit consideration. Graft options besides the ipsilatera1 palmaris include the gracilis or semitendinosis tendons, contralateral palmaris longus tendon, the plantaris tendon, the lesser toe extensors, or a 5-mm strip of the Achilles or flexor carpi radialis tendons.
AUTHORS' PREFERRED METHOD
The preoperative evaluation in the throwing athlete with UCL injury often identifies intra-articular pathology, which needs to be evaluated and addressed when the ligament is reconstructed. Also, some athletes with suspected ligament laxity can have equivocal opening on valgus stress examination. For these reasons, we often evaluate the elbow arthroscopically in conjunction with the ligament reconstruction procedure. The patient is positioned supine. A pneumatic tourniquet is used for hemostasis. The arm is placed in the over-the-chest position and the hand is held by an assistant or secured with an arm holder, such as the McConnell device (McConnell Orthopaedic Manufacturing Co., Greenville, TX). Routine arthroscopy portals are used to evaluate the elbow. The arthroscopic evaluation permits visualization of the anterior and posterior compartments. The anterior compartment is evaluated for loose bodies and spur formation. The capitellum surface is visualized for reciprocal chondral lesions seen in acute or long-standing UCL deficiency and for osteochondritis dessicans (OCD) lesions. Although only the anteriormost 20% to 30% of the anterior bundle is visible from the anterior portal, medial elbow stability can be assessed at 51 If the diagnosis of UCL incompetence is unclear, an arthro~copy.'~, arthroscopic stress test for the UCL can be perf~rmed.'~ With the elbow at 90" of flexion, the forearm is pronated and valgus stress is applied. In the normal elbow a maximum of 1 to 2 mm of medial opening will be observed. If the UCL is incompetent, greater than 3 mm of opening between the coronoid and medial humerus is observed. The posterior compartment also is evaluated for loose bodies. These athletes often have a medial olecranon spur in association with the valgus extension overload experienced during throwing.58Debridement of the spur is accomplished easily at arthroscopy. The chondral surfaces of the posterior compartment also are evaluated at arthroscopy. We have seen a characteristic reciprocal chondral lesion of the medial christa of the posterior humeral trochlea occurring in association with the olecranon spurring in throwers with UCL insufficiency. For these reasons, we
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have found arthroscopy to be a valuable adjunct to the evaluation and treatment of UCL injuries. After completion of the arthroscopy, the arm is abducted and externally rotated and placed on an arm board for the reconstruction procedure. The ipsilateral palmaris longus tendon is the preferred graft. Its presence must be confirmed during the preoperative exam. Otherwise, one of the alternative free tendon grafts mentioned earlier must be used. We now use a small tendon stripper to harvest the tendon, with only a single incision at the distal palmar crease. The harvest is faster and easier than the traditional two-incision technique, and there has been no associated morbidity from bleeding or median nerve trauma in our experience. The tendon is identified first through a transverse 5- to 10-mm incision at the distal palmar crease of the wrist. The tendon is mobilized using gentle blunt dissection, taking care to avoid the underlying median nerve and its palmar cutaneous branch. The distal tendon is cut at its insertion at the palmar fascia and advanced out the proximal incision. It is transected at the musculotendinous junction, providing a graft of approximately 15 cm. One end of the graft is secured with a #1 braided nonabsorbable suture using a Krakow stitch. After completing the graft preparation, the elbow reconstruction is begun. The arm is exsanguinated and the tourniquet inflated. A 10-cm curvilinear incision is made over the medial epicondyle, from the distal third of the intramuscular septum across the medial epicondyle to a point 2 cm beyond the sublime tubercle of the ulna. The fascia and aponeurosis of the flexor pronator group are exposed carefully and the medial antebrachial cutaneous nerve is isolated and protected. The nerve crosses the field anywhere from 3 to 60 mm distal to the epicondyle (Fig. 4).45If a previous ulnar nerve transposition has taken place, the ulnar nerve should be isolated and protected. This emphasizes the need for a thorough preoperative history. Once the flexor pronator has been exposed, there are two options for exposure of the ligament. The standard approach as described by Jobe involved transecting the conjoined tendon of the flexor-pronator and reflecting it distally to gain exposure to the medial capsule.25This has proven a reliable technique for ligament exposure, but we prefer the less traumatic muscle-splitting appr0ach.4~ The interval for the muscle split is the fascia1 raphe between the ulnar innervated flexor carpi ulnaris and the median innervated flexor mass. Usually, this raphe is identified easily at the posterior one third of the flexor pronator group (Fig. 5). The fascia is incised longitudinally along the raphe from the medial epicondyle, extending distally 1 cm distal to the sublime tubercle of the ulna, identified using deep fingertip palpation through the flexor mass. The ulnar nerve lies just posterior to this interval and should be identified and protected before completing the muscle split. The muscle fibers are split longitudinally in line with the fibers, using blunt dissection to expose the medial joint capsule. This interval separates the flexor carpi ulnaris (medial) from the palmaris longus (lateral) in the superficial dihsection, and in the deeper dissection
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Figure 4. The safe interval through which the muscle splitting incision is performed. Care must be taken to protect the medial antebrachial cutaneous nerve. MCL = medial collateral ligament. (From Smith GR, Altchek DW, Pagnani MJ, et al: A muscle-splitting approach to the ulnar collateral ligament of the elbow: Neuroanatomy and operative technique. Am J Sports Med 24:575-580,1996; with permission.)
separates the flexor carpi ulnaris from the flexor digitorum superficialis.& Once on the capsule, exposure of the medial ulna distal to the sublime tubercle is done using subperiosteal dissection to avoid transecting motor branches to the flexor carpi ulnaris. Anatomic dissection data identifying the points of motor branch innervation from both the median and
Figure 5. The incision through the raphe of the flexor pronator mass.
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ulnar nerves was used in developing the approach to avoid denervation of the surrounding muscle.45 Blunt retractors are used to retract the anterior and posterior muscle masses, to access the capsule and ligament. The ligament then is incised longitudinally, exposing the medial joint, to assess for intra-articular pathology. A valgus stress is applied with the elbow flexed 30", 60", and 90" to assess the ligament (Fig. 6 ) . The joint will open 3 to 4 mm with a As much as possible of valgus stress when the ligament is ins~fficient.~ the ligament origin and insertion should be preserved. The ligament and capsule can be closed later, before graft tensioning, in a pant-over-vest imbrication to add support to the reconstruction. The entire anterior bundle is exposed from its origin to the insertion on the ulna. The subperiosteal dissection is continued distally approximately 1 cm on the ulna to allow for graft tunnel placement. The alternative exposure described by Jobe entails transecting the tendinous origin of the flexor pronator origin 1 cm distal to the medial epicondyle and reflecting the tendon and muscle distally.25Although it allows excellent exposure to the ligament, this approach is more time consuming and more traumatic to the tissues. The authors prefer the muscle-splitting approach for its ease of exposure, low risk of muscle denervation, and potentially lower postoperative morbidity. If preoperative work-up indicates ulnar neuropathy, anterior transposition can be achieved easily through the muscle-splitting approach. The authors prefer a subfascial transposition. If a submuscular transposition is the sur-
Figure 6. The muscle splitting approach to the ulnar collateral ligament demonstrates the insertion of the anterior bundle on the sublime tubercle of the ulna.
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geon's preferred technique, the flexor pronator turndown would be the best approach for combining these procedures. Care must be taken to preserve the motor branches to the flexor carpi ulnaris. Graft fixation is achieved through bone tunnels in the ulna and medial epicondyle. Standard ulnar tunnels are created with convergent drill holes at the anterior and posterior margins of the sublime tubercle of the ulna separated by a 1 to 2-cm bone bridge.25The hard cortical surface of the tubercle provides an excellent bone bridge for graft fixation. Drill holes can be made using a 3.2-mm drill or a small #3 burr. The holes are connected under the bridge using small curved curette, taking care to preserve the bone bridge. For graft fixation in the medial epicondyle, Jobe originally described fashioning divergent drill holes from a single entry hole on the anterior distal e p i c ~ n d y l eWe . ~ ~have developed a technique of counter-sinking the proximal ends of the graft into a single unicortical drill hole at the same anterior distal origin of the anterior bundle and tensioning the graft over bone bridge sutures on the proximal epicondyle. Our technique uses a 3.2-mm drill or small #4 burr to create a 15mm cylindrical unicortical tunnel in the medial epicondyle preserving the proximal anterior cortex of the epicondyle. Two small 2.0-mm divergent drill holes, separated by 5 to 10 mm, are placed through the proximal anterior cortex of the medial epicondyle entering into the cylindrical graft docking tunnel (Fig. 7). A suture passer is used from each of the two upper humeral tunnels to pass a looped suture to be used later for graft passage. With the elbow reduced, the horizontal incision in the UCL is repaired using a 2-0 absorbable suture. The graft is passed through the ulnar tunnel, generally from anterior to posterior (Fig. 8). The limb of the graft that has sutures already placed is then passed into the humeral tunnel with the sutures pulled exiting one the small superior humeral tunnels. With this first limb of the graft securely docked in the humerus, the elbow is reduced with maximal forearm supination and gentle varus stress. While tension is maintained on the graft, the elbow is ranged from flexion to extension to eliminate potential creep in the graft. The final length of the graft then is measured by placing the free limb of the graft adjacent to the humeral tunnel and visually estimating the length of the graft that will allow the graft to be tensioned in the humeral tunnel. This point is marked with dye and a #1 braided nonabsorbable suture is placed in a Krackow fashion in the free end of the graft (Fig. 9). This end of the graft then is docked securely in the humeral tunnel with the sutures exiting the small superior humeral tunnel. Final graft tensioning is performed by again placing the elbow through a full range of motion with varus stress placed on the elbow. Once the surgeon is satisfied with the graft tension and isometry, the two sets of graft sutures are tied over the bone bridge on the humeral epicondyle (Fig. 10). The range of motion of the elbow is checked to assess final ligament isometry and a gentle valgus stress is applied in 60" of flexion to assess graft tension. The tourniquet is released, hemostasis is achieved, and the wound is irrigated copiously. We have not found the
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39
Figure 7. Convergent drill holes in the ulna anterior and posterior to the sublime tubercle with approximately 1-cm bone bridge. Divergent drill holes in the medial epicondyle.
need to drain the wound when the muscle-splitting technique is used. Closure for the muscle-splitting technique is simple. The fascia1 split is closed using interrupted #2-0 absorbable sutures. The skin is closed routinely with subcuticular suture. The arm is then placed in a bulky, light-compression splint with the arm in approximately 60" of flexion.. Using the divergent tunnel technique described by Jobe, the graft is advanced into one tunnel, around the epicondyle, and back through the second tunnel in a figure-of-eight fashi0n.2~The graft is tensioned and secured to itself. The authors prefer the unicortical tunnel technique for its ease of graft tensioning and secure bone bridge fixation. Care must be taken to fashion the tunnel in a cylindrical shape not conical) to allow the graft to countersink adequately into the tunnel during tensioning. The graft also must be cut precisely to allow adequate countersinking in the tunnel for bony ingrowth without making it too long, such that it cannot be tensioned in the confines of the tunnel. POSTOPERATIVE MANAGEMENT
The importance of a systematic rehabilitation program cannot be overemphasized. Close cooperation between the supervising surgeon,
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Figure 8. The graft is passed by advancing end with Krackow suture from anterior to posterior through the ulnar tunnel.
Figure 9. The ends of the tendons are inserted into the unicortical drill hole and the graft is countersunk into the tunnel and tensioned
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Figure 10. With the medial joint closed, the sutures are tied over the bone bridge.
therapist, athletic trainer, coaches, and athlete is essential. The authors currently use a six-phase progressive rehabilitation program on throwers after UCL reconstruction before beginning the graduated throwing phase of recovery. Phase 1is the first week postoperatively. The arm is immobilized in 60" of flexion. Gripping exercises are initiated with wrist range of motion and therapeutic modalities as needed. Phase 2 consists of weeks 1 to 4.The splint is removed at 1 week and a hinged elbow brace is applied under the surgeon's supervision. Range of motion of 40" to 90" allowed. Wrist and elbow isometrics are initiated. Shoulder isometrics, excluding internal and external rotation, also are begun. Manual scapular stabilization exercises are begun, and therapeutic modalities as needed. In phase 3 (4 to 6 weeks), the brace is opened to 20" to 110" at 5 weeks under the surgeon's supervision. Range of motion is increased gradually and light wrist and elbow isotonics are begun. Scapular and shoulder strengthening are advanced. Shoulder external rotation is avoided in an effort to avoid valgus stress to the elbow. Phase 4 consists of weeks 6 to 8. The brace is removed at 6 weeks under the surgeon's supervision. Wrist, elbow, and shoulder isotonics are progressed and external rotation in neutral shoulder abduction is initiated. Upper-body ergonometric exercises are begun. In phase 5 (8 to 10 weeks), wrist and elbow strengthening is advanced, stressing eccentrics. Aggressive shoulder strengthening is begun,
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including overhead rotator cuff exercises. Upper-body ergonometric endurance training is advanced and throwing patterns are begun. In phase 6 (10 to 13 weeks), aggressive upper-body strengthening is continued and plyometric training is initiated. Endurance training is continued and restoration of normal flexibility is emphasized. After completing this initial rehabilitation, interval throwing is initiated under the surgeon’s supervision and advanced between weeks 14 and 20. Light tossing, 30 to 40 feet, without a wind-up is begun, with two to three sessions a week for 10 to 15 minutes each. At 5 months, the distance is increased to 60 feet; at 6 months, an easy wind-up is added. Flexibility exercises are continued, and a total upper-body exercise program using the normal training principles is started. Ice is used after each training or throwing session to reduce inflammation. At 7 to 8 months, pitchers can return to the mound. The duration of the throwing sessions is increased to 25 minutes and effort progresses to 70% velocity during the eighth or ninth month. During the following 2 months, attention is focused on body mechanics and technique. Throwing sessions are lengthened and game simulation is begun. Competitive throwing is permitted at 9 months if upper-body range of motion and strength are normal and if the arm is pain free. Elite level pitchers may require 18 months to regain full preoperative proprioception, rhythm, and accuracyz5 RESULTS
Most overhead athletes undergoing UCL reconstruction are able to return to their previous level of function. In our series of 30 baseball players with 2-year follow-up, 29 of 30 (97%)have returned to their preinjury level of competition.2Another cohort of 33 patients with a minimum of 2-year follow-up demonstrated 93% excellent results in the subset of patients that were highly competitive athletes who had not had a prior surgical procedure.50In one series, 68% of overhead athletes (most of whom were baseball players) were able to return to their previous level of participati~n.~~ In this series, 50% of the repair group returned to their previous level. The time to recovery differed between the two groups, with the repair group averaging 9 months to return and the reconstruction group averaging 12 months. Those with previous operations on the elbow were shown to have a lower chance of returning to their previous level of participation. Of the various sport participants undergoing UCL reconstruction, baseball pitchers are the most difficult to return to their previous level of function. COMPLICATIONS
The most common postoperative complications following UCL reconstruction include trauma to the medial antebrachial cutaneous or
VALGUS INSTABILITY OF THE ELBOW IN ATHLETES
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ulnar nerves. In the authors’ series of 30 throwers at 2 years postoperatively, one patient required resection of a neuroma of the medial antebrachial cutaneous nerve and subsequently was diagnosed with reflex sympathetic dystrophy. The second complication occurred in a high school catcher who, while hitting at 7 months postoperatively, suffered a fracture of the ulnar tunnel.* This patient underwent successful revision reconstruction and has returned to high school baseball. Thompson et a1 reported on 83 reconstructions, in which 5% demonstrated transient ulnar nerve symptoms.50All neurologic symptoms in this group resolved with conservative management. Ulnar nerve irritation was noted in 21% of reconstructions in one series? Seven patients who had ulnar nerve transpositions with the primary reconstruction required a revision ulnar nerve procedure. We do not routinely transpose or release the ulnar nerve using the muscle-splitting approach and find most cases do not require ulnar nerve procedures. When the ulnar nerve is addressed, gentle handling and preservation of its vascular supply is essential. Meticulous hemostasis can prevent postoperative hematoma formation. We routinely address intra-articular pathology, such as loose bodies or osteophytes, with preliminary arthroscopy to avoid the need for a posterior arthrotomy near the ulnar nerve. Careful dissection during the approach to identify and protect the cutaneous nerves can prevent formation of painful neuromas. References 1. Albright JA, Jokl P, Shaw R, et al: Clinical study of baseball pitchers: Correlation of injury to the throwing arm with method of delivery. Am J Sports Med 6:15-21, 1978 2. Altchek D, Hyman JL, Williams RJ, et al: Ulnar Collateral Ligament Reconstruction in Throwers Using the “Docking” Technique: Two-Year Results. Sun Valley, ID, American Orthopaedic Association, 1999 3. Andrews JR, Timmerman LA: Outcome of elbow surgery in professional baseball players. Am J Sports Med 23:407413, 1995 4. Andrews JR, Whiteside JA: Common elbow problems in the athlete. J Orthop Sports Phys Ther 17289-295, 1993 5. Barnes DA, Tullos HS: An analysis of 100 symptomatic baseball players. Am J Sports Med 6:62-67,1978 6 . Barrentine SW, Fleisig GS, Whiteside JA, et al: Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow. J Orthop Sports Phys Ther 28:405415, 1998 7. Callaway GH, Field LD, Deng XH, et a1 Biomechanical evaluation of the medial collateral ligament of the elbow. J Bone Joint Surg Am 79:1223-1231, 1997 8. Ciccotti MG, Jobe Ew: Medial collateral ligament instability and ulnar neuritis in the athlete’s elbow. Instr Course Lect 48:383-391, 1999 9. Conway JE, Jobe FW,Glousman RE, et al. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 7467-83, 1992 10. Davidson PA, Pink M, Perry J, et al: Functional anatomy of the flexor pronator muscle group in relation to the medial collateral ligament of the elbow. Am J Sports Med 23245-250, 1995 11. Dillman CJ, Fleisig GS, Andrews J R Biomechanics of pitching with emphasis upon shoulder kinematics. J Orthop Sports Phys Ther 18:402-408, 1993 12. Elattrache NS,
McMahon PJ: Dislocations and collateral ligament injuries. In Hemdon, JH: Surgery Reconstruction of the Upper Extremity. Stamford, Appleton and Lange, 1999, pp 321331 13. Ellenbecker TS,Mattalino AJ, E l m EA, et a1 Medial elbow joint laxity in professional baseball pitchers. A bilateral comparison using stress radiography. Am J Sports Med 26420424,1998 14. Field LD, Altchek DW Elbow injuries. Clin Sports Med 1459-78,1995 15. Field LD, Altchek DW Evaluation of the arthroscopic valgus instability test of the elbow. Am J Sports Med 24377-181,1996 16. Field LD, Savoie FH: Common elbow injuries in sport. Sports Med 26:193-205, 1998 17. Fleisig GS, Andrews JR, Dillman CJ, et al: Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med 23:233-239, 1995 18. Floris S, Olsen BS, Dalstra M, et al.: The medial collateral ligament of the elbow joint: Anatomy and kinematics. J Shoulder Elbow Surg 7 3 5 3 5 1 , 1 9 9 8 19. Glousman RE, Barron J, Jobe FW, et al: An electromyographic analysis of the elbow in normal and injured pitchers with medial collateral ligament insufficiency. Am J Sports Med 20311-317, 1992 20. Hamilton CD, Glousman RE, Jobe FW, et a1 Dynamic stability of the elbow: Electromyographic analysis of the flexor pronator group and the extensor group in pitchers with valgus instability. J Shoulder Elbow Surg 5347-354, 1996 21. Hechtman KS, Tjin ATEW, Zvijac JE,et al: Biomechanics of a less invasive procedure for reconstruction of the ulnar collateral ligament of the elbow. Am J Sports Med 26620424,1998 22. Hotchkiss RN, Weiland AJ: Valgus stability of the elbow. J Orthop Res 5: 372-377,1987 23. Jobe FW, Elattrache N S Diagnosis and treatment of ulnar collateral ligament injuries in athletes. In Morrey B F The Elbow and Its Disorders. Philadelphia, WB Saunders, 1993, pp 566-572 24. Jobe FW, Elattrache N S Treatment of ulnar collateral ligament injuries in athletes. In Morrey B F Master Techniques in Orthopedic Surgery: The Elbow. New York, Raven Press, 1994, pp 149-168 25. Jobe FW, Stark H, Lombard0 SJ: Reconstruction of the ulnar collateral ligament in athletes. J Bone Joint Surg Am 68:1158-1163, 1986 26. Johnston J, Plancher KD, Hawkins RJ: Elbow injuries to the throwing athlete. Clin Sports Med 15:307-329, 1996 27. King J, Brelsford HJ, Tullos H S Analysis of the pitching arm of the professional baseball pitcher. Clin Orthop 67116-123, 1969 28. Lee GA, Katz SD, Lazarus M D Elbow valgus stress radiography in an uninjured population. Am J Sports Med 26:425-427, 1998 29. Lee ML, Rosenwasser MP: Chronic elbow instability. Orthop Clin North Am 30:8189,1999 30. London JT: Kinematics of the elbow. J Bone Joint Surg Am 63:529-535,1981 31. Mirowitz SA, London SL Ulnar collateral ligament injury in baseball pitchers: MR imaging evaluation. Radiology 185:573-576, 1992 32. Morrey B F Applied anatomy and biomechanics of the elbow joint. Instr Course Lect 35:59-68, 1986 33. Morrey BF, An KN: Articular and ligamentous contributions to the stability of the elbow joint. Am J Sports Med 11:315-319, 1983 34. Morrey BF, An KN: Functional anatomy of the ligaments of the elbow. Clin Orthrop 201:84-90, 1985 35. Morrey BF, Chao EY Passive motion of the elbow joint. J Bone Joint Surg Am 58:501-508, 1976 36. Morrey BF, Tanaka S, An KN: Valgus stability of the elbow. A definition of primary and secondary constraints. Clin Orthop 26537-195,1991 37. Nakanishi K, Masatomi T, Ochi T, et al: MR arthrography of elbow: Evaluation of the ulnar collateral ligament of elbow. Skeletal Radio1 25:629-634, 1996 38. Norwood LA, Shook JA, Andrews J R Acute medial elbow ruptures. Am J Sports Med 9%-19, 1981 39. Ochi N, Ogura T, Hashizume H, et a1 Anatomic relation between the medial collateral
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ligament of the elbow and the humero-ulnar joint axis. J Shoulder Elbow Surg 8610, 1999 ODriscoll SW, Jaloszynski R, Morrey BF, et al: Origin of the medial ulnar collateral ligament. J Hand Surg [Am] 17164-168,1992 Protzman Rl? Dislocation of the elbow joint. J Bone Joint Surg Am 60:539-541, 1978 Regan WD, Korinek SL, Morrey BF, et a1 Biomechanical study of ligaments around the elbow joint. C l i Orthop 271:170-179, 1991 Schwab GH, Bennett JB, Woods GW, et al: Biomechanics of elbow instability: The role of the medial collateral ligament. Clin Orthop 146:42-52, 1980 Schwartz ML, al-Zahrani S, Morwessel RM, et al: Ulnar collateral ligament injury in the throwing athlete: Evaluation with saline-enhanced MR arthrography. Radiology 197297-299, 1995 Smith GR, Altchek DW, Pagnani MJ, et al: A muscle-splitting approach to the ulnar collateral ligament of the elbow. Neuroanatomy and operative technique. Am J Sports Med 24575580,1996 Sojbjerg JO, Ovesen J, Nielsen S: Experimental elbow instability after transection of the medial collateral ligament. Clin Orthop 218:186-190, 1987 Sugimoto H, Ohsawa T: Ulnar collateral ligament in the growing elbow: MR imaging of normal development and throwing injuries. Radiology 192:417422, 1994 Suzuki K, Minami A, Suenaga N, et al: Oblique stress fracture of the olecranon in baseball pitchers. J Shoulder Elbow Surg 6:491494, 1997 Tan F, Lomasney LM, Demos TC: Radiologic case study. Ulnar collateral ligament injury. Orthopedics 21:827, 819-823, 1998 Thompson WH, Jobe FW, Yocum L A Ulnar collateral ligament reconstruction in throwing athletes: Muscle splitting approach without transposition of the ulnar nerve [abstract]. J Shoulder Elbow Surg 7175, 1998 Timmerman LA, Andrews JR Histology and arthroscopic anatomy of the ulnar collateral ligament of the elbow. Am J Sports Med 22667473,1994 Timmerman LA, Andrews J R Undersurface tear of the ulnar collateral ligament in baseball players. A newly recognized lesion. Am J Sports Med 22:33-36, 1994 Timmerman LA, Schwartz ML, Andrews J R Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation. Am J Sports Med 22:26-31 [discussion, 321, 1994 Tullos HS, King JW: Throwing mechanism in sports. Orthop Clin North Am 4: 709720, 1973 Tullos HS, Schwab G, Bennett JB, et al: Factors influencing elbow instability. Instr Course Lect 30:185-199, 1981 Veltri DM, OBrien SJ, Field LD, et al: The milking manuever: A new test to evaluate the MCL of the elbow in the throwing athlete. J Shoulder Elbow Surg 4520, 22, 1995 Werner SL, Fleisig GS, Dillman CJ, et al: Biomechanics of the elbow during baseball pitching. J Orthop Sports Phys Ther 17276278,1993 Wilson FD, Andrews JR, Blackbum, TA, et al: Valgus extension overload in the pitching elbow. Am J Sports Med 11:83-88, 1983 Xue 0,Masuda K A biomechanical study of fast throwing movements of the shoulder in baseball pitching. Chin Med J (Engl) 110:220-224, 1997
Address reprint requests to David W. Altchek, MD Sports Medicine and Shoulder Service The Hospital for Special Surgery Cornell University Medical Center 535 East 70th Street New York, NY 10021